Pneumatic-piano construction



C. E. PETEHEBON Oct. 6, 1925- PNEUMATI C PI 1N0 CONSTRUCTION Filed Aug. 25; 19 22 Patented Oct. 6, 1925.

CLAUS E. PETERSON. O3? WORCESTER. liIILESAU i e i q PNEUMATIC-PIANO CONSTRUCTIDN.

Application filed August 1922.

l all whom it may concern Be it known that I. CLAUs E. a citizen of the United States, residing at \Vorcester, in the county of \Vorcester and Commonwealth of Massachusetts, have vented a new and useful Improvement in a Pneumatic-Piano Construction, of which the following, together with the accompanying drawings, is a specification.

The present invention relates to improvements in the construction of pneumatic pianos, adapted to simplify and render compact the assemblage of operating parts therein, while at the same time insuring the maintenance at all times of the full operating suction, in spite of atmospheric changes tending to produce leakage i the connections between tie parts. The above and other objects are attained by the construction hereinafter described in detail. reference being had to the accompanying drawings, wherein Fig. 1 is a side view, partly in section, of a pneumatic player action embodying the invention.

Fig. 2 is a front view, on a smaller scale, of the vacuum chamber of such an action. with a part of the cover removed.

Fig. 3 is a top plan view of the valve mechanism.

Fig. 4 is a perspective view of the valve.

Like reference characters refer to like parts in both figures.

In Fig. 1 is shown the usual tracker bar 1, over which passes the travelling perforated note sheet 2 which is wound up on a spool 3, as is customary in mechanism of this class. Each tracker bar aperture 1- has associated therewith an actuating pneumatic. of the general type illustrated at 5, 5, Fig. 1; these pneumatics, all under the action of a common suction, operate through their movable leaves 6 on the wippen T, to cause the striking of notes in conformity to the registration of the note sheet and tracker bar apertures.

According to the invention, all of the pneumatics are connected to and supported by the inner wall 8 of a common vacuum chamber 9, the latter extending the full length of the action. As shown in Fig. 2, the pneumatics carried by said wall 8 are arranged in staggered relation to economize space, and the attachment of each is by a pair of screws 10, 10, passing through said wall and projecting into the ETERSOX Serial No.

end of each pneumatic bloeli. E2161.) traeic r bar RPQTJDIHQ has ation with respective pueuma connection and a rigidlymo: each i is disposed i t1 vacuum ber i w. i

unatic. connections for alt of the pneui 5 are carried di and within the vacuum chamber 9 which supports said .ieuamtics,it be- A uni the i l 5,5 o

chamber is rendered imperforate and proof at the various points of insertion or, the portions 18 and i i of tubes 12 by soidering or the like.

In common with the usual practice in mechanism of this class, each actuating pneuamtic has associated therev-Iith a bleed opening; the arrangement of the apparatus, as above described, lends itself to the dis posal of the bleed opening for each pneumatic in its associated tube 12, as showi'i at 16, 16. In this position, each bleed opening is readily accessible, simply by the removal of a screw or plug 1? appropriately disposed in the cover plate 18 of va-ziiuum chamber 9, which cover plate is attached by suitable screws 19 to a flange of rear wall 8. Upon the wal of any screw or plug 17, a! wire may be inserted tln'ough the opening of the cover plate to clean out the associated bleed opening 16, without otherwise disturbing the arrangement and assemblage of the parts.

According to the invention, each actuating pneumatic 5 is constructed as shown in section at the bottom of Fig. 1 with the pneumatic block 20, which supports and contains the valve mechanism and which serves for the attachment of the device by the screws 10, 10, of tary one-piece (,(lllbcl'iP- tion, without any gluing or joints. To this end, each block 20 is formed with two recesses 21 and the latte communicating y a pasage with the vacuum chamber 9 and having therein a shoulder for the attaclnn the usual pulsating diaphragm 25, below which enters the passage from the associated tube 11. The block or stationary portion of the pneumatic 5, preferably of wood, is thus so constructed as to be unaffected by atmospheric or moisture conditions, since there are no glued 'oints or screw attachments to be adversely aected either by shrinkage or swelling of the material.

The recess 21 serves, as usual, for communication to the atmosphere, and the recess 22 for the operation of a valve device 26, under the influence of diaphragm 25. To this end, the block is surmounted b a suitable valve chamber, composed pre erably entirely of metal, and here shown as consisting of a flanged bottom member 27 and a top or cover member 28, the latter inclosing between them a space 29 which is enlarged at 30 to accommodate valve 26'. The member 27 has two bottom apertures in registration with apertures of the same size in block 20, and connecting respectively with the recesses 21 and 22; these registering apertures are adapted to receive the short metallic tubular connecting members 31 and 32, respectively, whose edges are flanged over and clinched, as shown at 38, to secure the member 27 rigidly to the block and to furnish permanent leak proof communication, unaffected by shrinkage or swelling of the material between the valve space and the respective recesses 21 and 22. In this way, the necessity for providing a metallic seat for the valve 26 is avoided; the tubular connecting member 32 itself forms the valve seat, besides serving to hold the valve casing in substantially integral relati'dnshi to the pneumatic block 20. The bottom p ate member 27 provides cars or In s 34 projecting from its edge or flange, wh ch are adapted to be turned down upon the top plate 28' to hold the latter, and its usual gasket, in place.

The mechanism operates and functions in the usual way, with the position of valve 26 directly responsive to the pulsation of diaphragm 25, the latter being actuated whenever a note sheet perforation comes into registration with the associated tracker bar opening; this causes a movement of leaf 6 to actuate the wippen 7. The valve member proper has secured to its under side a plate 35, which provides a circular series of projecting cars 36 disposed within the member 32 and operating as guides for the up and down movement of said valve.

I claim,

1. In a pneumatic player action, a rear wall and cover plate comprising a vacuum chamber, a plurality of actuating neumatics having tracker-bar connections, said trackerbar connections inclosed in said vacuum chamber, bleeds in said connections, and individual means of access in the cover plate of said vacuum chamber to said bleeds.

2. An actuating pneumatic, providing a stationary section with recesses, and a super imposed va'l've casing, with flanged-over tubular members connecting said parts and affording communications between the valve casing and the said recesses.

3. An actuating pneumatic, comprising a stationary one piece member with a recess in the under side, a valve casing above said member and a tubular connection through said member having flanges, with one flange projecting into said recess and another flange projecting into said casing, securing the easing to the one iece member and affording communication tween them.

4. An actuating pneumatic for player actions, comprising a wooden stationary block, a' recess in the under sitieof said block, a valve casing above said block and a. tubular connection throu h said member havin flanges, with one ang'e projecting into sai casing, securing the casin to the block and ail'ordine communication tween the recess in said lock and the casing.

5. An actuating pneumatic for pla or actions, comprising a stationar woo en block, a recess on the under si e of said block to contain a diaphragm, said recess extending entirely through said block, another recess through said block connecting with the bellows chamber, a. valve casing abdve said blobk connecting with both recesses, said valve chamber being made of pressed metal, and flanged over tubular members connecti ng bothof said recesses to said valve easing.

6. A valve casin for an actuating pneumatic unit made em two pieces of sheet metal generally oblong in shape, one member having flanges to be turned over upon the other members securing a gasket therebetween, the top piece having a pressed out portion to receive a valve, and the bottom piece having two apertures therein for pneumatic connection with two recesses in the said unit.

7 In an actuating pneumatic unit, a valve casing made from two generally oblong pieces of sheet metal, a pair of flanged over tubular members connecting one of said pieces to a pair of recesses in said unit by cooperation with holes made in said piece, and ears on one of sad pieces to connect the said pieces with a gasket therebetwecn.

CLAUS E. PETERSON. 

